Should I NOT go to work on 29th October (a national holiday) and risk to get fired or being bullied by co-mates and the boss?

Yes, you must go no matter what, even if you are not getting extra paid or something. even if there is a law everyone will be exploited anyway, so will you.

No, on a national holiday you mustn't work no matter what the consequences are, It is your right according to the law.